Grasses

Oh no! I think I know the one you mean. Is it evergreen? With long seedheads? That can grow pretty quickly. It's very useful in areas that need greenery in the winter, but no good in a small garden.

I had an old chest freezer at one house. I took the lid off and painted it with hammerite, put it in a corner of the patio and filled it with grasses and a clematis at the back. It worked very well.

A miscanthus, perhaps? Biggish plumes? I have a couple that need digging out, halving and replanting. The bases are so tough that you have to use a saw to get through the roots.

I think before you go away would be a good idea. That'll give it time to settle and quieten down before it's growth next year.

Do you think I should wait until next year or do this before I go away.

Yes, good idea. Keep it fed in the growing season.